|“||It will bring you light, even among the darkest shadows of this world and others.||”|
Witchlight is a light, flat, smooth gray stone that emits light, giving off a pure white glow when held by Shadowhunters. All Shadowhunters carry witchlight stones to remind them that light can be found even among the darkest shadows, and also to supply them with actual light when they are literally among dark shadows. According to Jace Herondale's notes in the Shadowhunter's Codex, Shadowhunters typically carry two witchlights.
Witchlight stones are said to be extracted from the same rock adamas is extracted from. The stone is affected by the presence of adamas, considered its "sister stone", and receives its glow from it, as though reflecting the light inherent in the heavenly metal. The stones are then broken up and polished by Iron Sisters, and Marked to make their glow a property that can be turned on and off at the will of the Shadowhunter holding them.
Although witchlight normally does not respond to the touch of mundanes and Downworlders, it glows a deep red, instead of the usual bright white, when held by Magnus Bane, as a result of his ancestry, as his father, Asmodeus, is a fallen angel.
While the glow of witchlight stones never fade or dissipate, it can still be destroyed by pulverizing the stone into dust; upon the destruction of the stone, the angelic light absorbed within it will dissipate; as a result, one never finds "witchlight sand" or the like.
In Nephilim society
The largest single witchlight crystal in the world can be found in the Silent City in the form of the Angelic Colossus, a representation of the Triptych, the familiar motif of Raziel ascending from the water of Lake Lyn, wielding the Mortal Instruments. The crystal stands roughly thirty feet tall, and it guards and lights the entrance to the Silent Brothers' living quarters. The Colossus is rarely seen by anyone other than the Silent Brothers, however, so those interested in large installations of witchlight are encouraged to visit the Cluj Institute, where the renowned Vampire Arch forms the threshold to the Institute. The Arch was built under the belief that vampires were sensitive to the holy light of witchlight, and would ultimately recoil from it, thus protecting the Institute. Though this fact was later disproved, the Arch was kept as it was and maintained as a symbolic monument.
Witchlight, being light of natural angelic origin, slightly burns the skin of vampires, though to a much lesser extent in comparison to sunlight. Also, Alicante is lit and powered primarily by witchlight, as are those rare roads that have been illuminated. While most Institutes today are wired for electricity, or, at worst, gaslight, witchlight is still often used for atmospheric effect, as a backup in places where electrical supply may be unreliable, or still as a primary source of energy in more historically besieged areas or remote locations, either too warded or too far from mundane civilization to use modern power sources.
- A similar light is used in the London Institute as lighting. At one point, Henry Branwell created the Phosphor, which was meant to be a more powerful form of witchlight, but it ultimately malfunctioned, and a successful version was never created.
- The Lightwood family necklace was once able to function as a witchlight.